All-optical switching system and method thereof

ABSTRACT

The present invention provides an all-optical switching system and the method thereof. The system comprises: N 1×M splitters for receiving N sets of optical data I 1 , I 2 , . . . , I N  wherein said N splitters individually split said N sets of optical data separately to form a N×M matrix of optical data, wherein N and M are integers ; a N×M matrix switching structure for receiving the N×M matrix of optical data generated by the N splitters and another driving signal matrix to generate N×M matrix of optical data; and M N×1 combiners for receiving the N×M matrix of optical data from the N×M matrix switching structure to combine them into M sets of optical data O 1 , O 2 , . . . , O M−1 , O M , respectively.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a highly efficient all-opticalswitching system and the method thereof. With the method provided by thepresent invention the transmission rate of the optical fibercommunication network increases a lot.

[0003] 2. Related Art

[0004] Along with the rapid growth of the Internet and mobile phoneusers, the demand of the data transmission rate and the need of thebroad-band communication are getting higher and higher. It is a trend inthe future to use the optical fiber network with the light as a mediumof transmission. Although the data on the optical fiber network istransmitted in the form of light, a router of the optical fiber networkcould only routes electrical signals. Thus when the optical data istransmitted to a routing point, it has to be converted into electricaldata first. After the electrical data is routed by the electrical router(switching system), it has to be converted back into the optical dataand to be transmitted by the optical fiber network subsequently. Such“optical data—electrical data—optical data” (O-E-O) routing mode notonly costs higher but also reduces the transmission rate of the opticaldata and becomes a bottle-neck of the transmission rate of the opticalfiber network.

[0005] There are several conventional all-optical switching devices(optical data—optical data—optical data, O-O-O) of communication networkas follows.

[0006] 1. A device which utilizes movable mirrors to do the lightswitching (refer to U.S. Pat. No. 4,580,873);

[0007] 2. A device which utilizes refraction of air bubbles to do thelight switching (refer to U.S. Pat. No. 4,988,157);

[0008] 3. A device which utilizes movable fibers and the principle ofmagnetic field to do the light switching (refer to U.S. Pat. No.6,169,826);

[0009] 4. A device which utilizes movable fibers and the principle of aspiral motor to do the light switching (refer to ROC Patent PublicationNos. 296,806 and 289,441);

THE DISADVANTAGES OF THE PRIOR ARTS

[0010] 1. To Use the Movable Mirrors to Do the Light Switching

[0011] This is a kind of mechanical rotating apparatus whose rotatingshaft of the mirrors might affect the light signal transmission withwrong rotating angles caused by mechanical fatigue. It is hard to detectif there is anything wrong with the rotating angle of the mirrors, andthe cost of maintenance is high. Besides, a n×m switching structure (ninput light signals and m output light signals) needs n×m mirrors. Sincethere is a limit to reduce the mirrors in size, the system is huge. Thearea of a 64×64 switching structure will be 256 times of that of the 4×4switching structure in size.

[0012] 2. To Use the Refraction of Air Bubbles to Do the Light Switching

[0013] It is similar to the principle of the mirror refraction mentionedabove, but it is liquid bubble used for refraction in this case. Whenthe light passes the liquid, it is refracted by the bubble generatedfrom the liquid. The liquid in the envelopes will be vaporized after along time usage or the tiny dust will enter the envelopes due to theuntight envelopes which might affect the generated bubbles and causeinaccurate refraction angle. It will be hard to refill the envelopesafter the liquid is vaporized if the envelopes are too tight. Also it isneeded to detect the status of the liquid often. The cost formaintenance is high.

[0014] 3. To Use the Movable Fibers and the Principle of the MagneticField to Do the Light Switching

[0015] This method only applied to one-dimensional switching device(1×N) and is actually hard to apply to two-dimensional switching device(N×M).

[0016] 4. To Use the Movable Fibers and the Principle of the SpiralMotor to Do the Light Switching

[0017] This method only applied to one-dimensional switching device(1×N) and is actually hard to apply to two-dimensional switching device(N×M).

[0018] The most serious disadvantage of the above mentioned four methodsis that they can not be commercially mass produced. There are someserious problems of the reliability and the cost to be resolved.

SUMMARY OF THE INVENTION

[0019] This invention utilizes “optical data—optical data—optical data”(O-O-O) switching mode to switch the light directly and to avoid thedisadvantage of the low transmission rate of the conventional (O-E-O)switching system and improve the disadvantages of the conventional(O-O-O) switching system.

[0020] This invention is to provide a feasible, highly-efficientall-optical switching system and a method thereof. To use the methodprovided by this invention will increase the transmission rate of theoptical fiber communication network.

[0021] This invention provides an all-optical switching system and itsmethod. The system comprises: N 1×M splitters for receiving N sets ofoptical data I₁, I₂, . . . , I_(N−1), I_(N). Said N splitters split saidN sets of optical data into M sets of optical data respectively andgenerate a N×M matrix D of optical data as follows: $D = \begin{bmatrix}D_{1,1} & D_{1,2} & \ldots & D_{1,{M - 1}} & D_{1,M} \\D_{2,1} & D_{2,2} & \ldots & D_{2,{M - 1}} & D_{2,M} \\\vdots & \vdots & ⋰ & \vdots & \vdots \\D_{{N - 1},1} & D_{{N - 1},2} & \ldots & D_{{N - 1},{M - 1}} & D_{{N - 1},M} \\D_{N,1} & D_{N,2} & \ldots & D_{N,{M - 1}} & D_{N,M}\end{bmatrix}$

[0022] wherein N and M are integers, the M sets of optical data D_(1,1),D_(1,2), . . . , D_(1,M−1), D_(1,M) are generated by the first 1×Msplitter by splitting the first optical data I₁, and D_(1,1)=D_(1,2)= .. . =D_(1,M−l)=D_(1,M)=I₁. On the analogy of this, an N×M matrixswitching structure to receive the N×M matrix D of optical datagenerated by the splitters and receive another driving signals matrix Ssimultaneously as follows: $S = \begin{bmatrix}S_{1,1} & S_{1,2} & \ldots & S_{1,{M - 1}} & S_{1,M} \\S_{2,1} & S_{2,2} & \ldots & S_{2,{M - 1}} & S_{2,M} \\\vdots & \vdots & ⋰ & \vdots & \vdots \\S_{{N - 1},1} & S_{{N - 1},2} & \ldots & S_{{N - 1},{M - 1}} & S_{{N - 1},M} \\S_{N,1} & S_{N,2} & \ldots & S_{N,{M - 1}} & S_{N,M}\end{bmatrix}$

[0023] and generates an N×M matrix D′ of optical data as follows:$D^{\prime} = \begin{bmatrix}D_{1,1}^{\prime} & D_{1,2}^{\prime} & \ldots & D_{1,{M - 1}}^{\prime} & D_{1,M}^{\prime} \\D_{2,1}^{\prime} & D_{2,2}^{\prime} & \ldots & D_{2,{M - 1}}^{\prime} & D_{2,M}^{\prime} \\\vdots & \vdots & ⋰ & \vdots & \vdots \\D_{{N - 1},1}^{\prime} & D_{{N - 1},2}^{\prime} & \ldots & D_{{N - 1},{M - 1}}^{\prime} & D_{{N - 1},M}^{\prime} \\D_{N,1}^{\prime} & D_{N,2}^{\prime} & \ldots & D_{N,{M - 1}}^{\prime} & D_{N,M}^{\prime}\end{bmatrix}$

[0024] M sets of N×1 combiners receive the N×M matrix D′ of optical dataoutput from the N×M matrix switching structure. Said M sets of combinerscombine N sets of optical data respectively to generate M sets ofoptical data O₁, O₂, . . . , O_(M−1), O_(M), wherein the first outputoptical data O₁ is generated by the first combiner after combining Nsets of optical data D′_(1,1), D′_(2,1), . . . , D′_(N−1,1), D′_(N,1),on the analogy of this.

[0025] In order to make the technical contents and characteristicseasier to be understood, the preferred embodiment is introduced with thebrief description of the drawings as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] This invention will become better understood with reference tothe accompanying drawings in which:

[0027]FIG. 1 shows this invention, all-optical switching system of thepresent invention;

[0028]FIG. 2A is the input-output relationship of a 1×4 splitter;

[0029]FIG. 2B is the input-output relationship of a 1×2 splitter;

[0030]FIG. 3 is a LCD N×M matrix optical switching structure when N=M;

[0031]FIG. 4A is the input-output relationship of a 4×1 combiner;

[0032]FIG. 4B is the input-output relationship of a 2×1 combiner;

[0033]FIG. 5A is a perspective view of a LCD on/off switching table;

[0034]FIG. 5B is a top view of an LCD on/off switching table;

[0035] FIGS. 6A-6Q show the input-output relationships of an LCD 4×4matrix optical switching system.

LIST OF REFERENCE NUMERALS OF THE MAJOR PARTS IN THE DRAWINGS

[0036]2 all-optical switching system

[0037]3 optical fiber

[0038]4 splitter

[0039]6 N×M matrix switching structure

[0040]8 combiner

[0041]9 optical fiber

[0042]18 LCD N×M matrix optical switching structure

[0043]32, 34, 36 input fibers

[0044]40, 42, 44 output fibers

DETAILED DESCRIPTION OF THE PREFERRED EMBODYMENT

[0045] A preferred embodiment of the present invention will be describedbelow with reference to the accompanying drawings. The same element inthe drawings is represented with the same reference numeral.

[0046]FIG. 1 shows an all-optical switching system of the presentinvention. FIG. 1 illustrates the relationship among the N sets ofsplitters 4, LCD N×M matrix optical switching structure 6 and M sets ofcombiners 8.

[0047] As shown in FIG. 1, the important characteristics of thestructure of the present invention is that the present invention uses an(O-O-O) switching mode to switch the light directly, in comparison withthe prior art (O-E-O) mode. Thus the disadvantage of the bottle-neck ofthe transmission rate of the prior art (O-E-O) system could be avoided.

[0048] As shown in FIG. 1 the N sets of optical data I₁, I₂, . . . ,I_(N−1), I_(N) are split by N 1×M splitters 4. N×M optical data matrixis generated as shown below: $D = \begin{bmatrix}D_{1,1} & D_{1,2} & \ldots & D_{1,{M - 1}} & D_{1,M} \\D_{2,1} & D_{2,2} & \ldots & D_{2,{M - 1}} & D_{2,M} \\\vdots & \vdots & ⋰ & \vdots & \vdots \\D_{{N - 1},1} & D_{{N - 1},2} & \ldots & D_{{N - 1},{M - 1}} & D_{{N - 1},M} \\D_{N,1} & D_{N,2} & \ldots & D_{N,{M - 1}} & D_{N,M}\end{bmatrix}$

[0049] Said N×M optical data matrix D is projected on the LCD N×M matrixoptical switching structure 6. After selection of a N×M driving signalmatrix S, an output optical data matrix D′ is generated, wherein${S = \begin{bmatrix}S_{1,1} & S_{1,2} & \ldots & S_{1,{M - 1}} & S_{1,M} \\S_{2,1} & S_{2,2} & \ldots & S_{2,{M - 1}} & S_{2,M} \\\vdots & \vdots & ⋰ & \vdots & \vdots \\S_{{N - 1},1} & S_{{N - 1},2} & \ldots & S_{{N - 1},{M - 1}} & S_{{N - 1},M} \\S_{N,1} & S_{N,2} & \ldots & S_{N,{M - 1}} & S_{N,M}\end{bmatrix}},{D^{\prime} = \begin{bmatrix}D_{1,1}^{\prime} & D_{1,2}^{\prime} & \ldots & D_{1,{M - 1}}^{\prime} & D_{1,M}^{\prime} \\D_{2,1}^{\prime} & D_{2,2}^{\prime} & \ldots & D_{2,{M - 1}}^{\prime} & D_{2,M}^{\prime} \\\vdots & \vdots & ⋰ & \vdots & \vdots \\D_{{N - 1},1}^{\prime} & D_{{N - 1},2}^{\prime} & \ldots & D_{{N - 1},{M - 1}}^{\prime} & D_{{N - 1},M}^{\prime} \\D_{N,1}^{\prime} & D_{N,2}^{\prime} & \ldots & D_{N,{M - 1}}^{\prime} & D_{N,M}^{\prime}\end{bmatrix}},$

[0050] said N×M optical data matrix D′ flows through M combiners 8 andis combined into M sets of output optical data O₁, O₂, . . . , O_(M−1),O_(M). The so-called selection means that the N×M driving signal matrixS determines the input-output relationship of elements of the LCD N×Mmatrix optical switching structure 6. When S_(P,Q) is 1 (0<P≦N, 0<Q≦M)D′_(P,Q)=D_(P,Q). When S_(P,Q) is 0, D′_(P,Q)=0. When S_(P,Q) is R(R≠0,1), D′_(P,Q)=D_(P,Q)×R

[0051] The so-called matrix optical switching structure is a switchingstructure which could determine by control whether the optical dataprojected on it could or could not pass through it. The LCD N×M matrixoptical switching structure 6 is one of the matrix optical switchingstructures.

[0052] The driving signal matrix S could be provided by a drivingsystem, or more specifically, by a computer.

[0053]FIGS. 2A and 2B illustrate the splitters. FIG. 2A shows a 1×4 (1to 4) splitter 4, wherein I₁ is an input optical data from an opticalfiber 3. After split by the splitter 4, four same output signals I₁ areoutput by four different optical fibers 38, 40, 42, 44. FIG. 2B shows a1×2 (1 to 2) splitter 4, wherein I₁ is an input optical data from anoptical fiber 3. After repeatedly split by the splitter 4 four sameoutput signals I₁ are output by the four different optical fibers 38,40, 42, 44.

[0054]FIG. 3 shows an LCD N×M matrix optical switching structure 18,when N=M, wherein N AND M are integers larger than or equal to 1.

[0055]FIGS. 4A and 4B show combiners 8. FIG. 4A shows a 4×1 (4 to 1)combiner 8, wherein I₁, I₂, I₃, I₄ are four different optical signals.O₁ is an output optical data from the optical fiber 9. FIG. 4B shows a2×1 (2 to 1) combiner 8, wherein I₁, I₂, I₃, I₄ are four different inputoptical signals. O₁ is an output optical data from an optical fiber 9.

[0056]FIGS. 5A and 5B are a perspective view and top view of an LCDon/off switching structure, respectively. When the LCD is on (logic 1),the optical data could pass through an LCD N×M matrix optical switchingstructure 18 to a combiner. When the LCD is off (logic 0), the opticaldata could not pass through the LCD N×M matrix optical switchingstructure 18 to the combiner.

[0057]FIGS. 6A to 6Q show the input-output relationships of theall-optical switching system using the LCD 4×4 matrix switchingstructure according to the preferred embodiment. FIG. 6A indicates that4 sets of optical data I₁, I₂, I₃, I₄ flow through 4 input opticalfibers 30, 32, 34 and 36 into four different splitters 4 respectively.After split by the splitters, said 4 sets of optical data I₁, I₂, I₃, I₄generate a 4×4 optical data matrix as below: ${D = \begin{bmatrix}D_{1,1} & D_{1,2} & D_{1,3} & D_{1,4} \\D_{2,1} & D_{2,2} & D_{2,3} & D_{2,4} \\D_{3,1} & D_{3,2} & D_{3,3} & D_{3,4} \\D_{4,1} & D_{4,2} & D_{4,3} & D_{4,4}\end{bmatrix}},$

[0058] wherein D_(1,1)=D_(1,2)=D_(1,3)=D_(1,4)=I₁, on the analogy ofthis. The data in the 4×4 optical data matrix pass through the LCD 4×4matrix switching structure and are combined by the combiners. 4 outputoptical data O₁, O₂, O₃, O₄ generated by the combiners are output by 4output optical fibers 38, 40, 42 and 44, respectively.

[0059]FIGS. 6B to 6Q indicate the input-output relationships of thedifferent driving signals matrices. For example, In FIG. 6B, when thedriving signal matrix ${S = \begin{bmatrix}1 & 0 & 0 & 0 \\0 & 0 & 0 & 0 \\0 & 0 & 0 & 0 \\0 & 0 & 0 & 0\end{bmatrix}},$

[0060] in the N×M optical data matrix ${D = \begin{bmatrix}D_{1,1} & D_{1,2} & D_{1,3} & D_{1,4} \\D_{2,1} & D_{2,2} & D_{2,3} & D_{2,4} \\D_{3,1} & D_{3,2} & D_{3,3} & D_{3,4} \\D_{4,1} & D_{4,2} & D_{4,3} & D_{4,4}\end{bmatrix}},$

[0061] only the optical data D_(1,1) can pass through the LCD 4×4 matrixswitching structure to the combiner. All the other optical data couldnot pass the LCD 4×4 matrix switching structure. Thus, after passing theLCD 4×4 matrix switching structure, the 4×4 optical data matrix becomes$\begin{bmatrix}D_{1,1}^{\prime} & 0 & 0 & 0 \\0 & 0 & 0 & 0 \\0 & 0 & 0 & 0 \\0 & 0 & 0 & 0\end{bmatrix},$

[0062] wherein D′_(1,1)=I₁. The four sets of output optical data O₁, O₂,O₃, O₄=D′_(1,1); 0, 0, 0=I₁, 0, 0, 0. FIGS. 6C to 6Q are on the analogyof this.

[0063] From the invention thus described, it will be obvious that theembodiments and description are not indeed to limit the invention. Theinvention may be varied in many ways. Such variations are not to beregarded as a departure from the spirit and scope of the invention, andall such modifications as would be obvious to one skilled in the art areintended for inclusion within the scope of the following claims.

What is claimed is:
 1. An all-optical switching system, comprising: N1×M splitters for receiving N sets of optical data I₁, I₂, . . . ,I_(N−1), I_(N), wherein said N splitters split the N sets of opticaldata respectively into M sets of optical data to form an N×M opticaldata matrix D as below: ${D = \begin{bmatrix}D_{1,1} & D_{1,2} & \ldots & D_{1,{M - 1}} & D_{1,M} \\D_{2,1} & D_{2,2} & \ldots & D_{2,{M - 1}} & D_{2,M} \\\vdots & \vdots & ⋰ & \vdots & \vdots \\D_{{N - 1},1} & D_{{N - 1},2} & \ldots & D_{{N - 1},{M - 1}} & D_{{N - 1},M} \\D_{N,1} & D_{N,2} & \ldots & D_{N,{M - 1}} & D_{N,M}\end{bmatrix}};$

 wherein N AND M are integers, D_(1,1), D_(1,2), . . . , D_(1,M−1),D_(1,M) represent the M sets of optical data split from the firstoptical data by the first 1×M splitter, on the analogy of thisrepresentation; an N×M matrix switching structure for receiving the N×Moptical data matrix D generated by the splitters and to receive anotherdriving signal matrix S as below: ${S = \begin{bmatrix}S_{1,1} & S_{1,2} & \ldots & S_{1,{M - 1}} & S_{1,M} \\S_{2,1} & S_{2,2} & \ldots & S_{2,{M - 1}} & S_{2,M} \\\vdots & \vdots & ⋰ & \vdots & \vdots \\S_{{N - 1},1} & S_{{N - 1},2} & \ldots & S_{{N - 1},{M - 1}} & S_{{N - 1},M} \\S_{N,1} & S_{N,2} & \ldots & S_{N,{M - 1}} & S_{N,M}\end{bmatrix}};$

 and for generating another N×M optical data matrix D′ as below:${D^{\prime} = \begin{bmatrix}D_{1,1}^{\prime} & D_{1,2}^{\prime} & \ldots & D_{1,{M - 1}}^{\prime} & D_{1,M}^{\prime} \\D_{2,1}^{\prime} & D_{2,2}^{\prime} & \ldots & D_{2,{M - 1}}^{\prime} & D_{2,M}^{\prime} \\\vdots & \vdots & ⋰ & \vdots & \vdots \\D_{{N - 1},1}^{\prime} & D_{{N - 1},2}^{\prime} & \ldots & D_{{N - 1},{M - 1}}^{\prime} & D_{{N - 1},M}^{\prime} \\D_{N,1}^{\prime} & D_{N,2}^{\prime} & \ldots & D_{N,{M - 1}}^{\prime} & D_{N,M}^{\prime}\end{bmatrix}};{and}$

M N×1 combiners for receiving the N×M optical data matrix D′ from theN×M matrix switching structure, wherein said M combiners combine N setsof optical data into M sets of optical data O₁, O₂, . . . , O_(M−1),O_(M) respectively, and the first optical data O₁ is generated by thefirst combiner after combining N sets of optical data D′_(1,1),D′_(2,1), . . . , D′_(N−1,1), D′_(N,1), on the analogy of thisgeneration.
 2. The all-optical switching system of claim 1, wherein saidN×M matrix switching structure is an LCD N×M matrix optical switchingstructure.
 3. The all-optical switching system of claim 1, wherein saidN sets of optical data I₁, I₂, . . . , I_(N−1), I_(N) received by said N1×M splitters are input by N optical fibers.
 4. The all-opticalswitching system of claim 1, wherein said M sets of optical data O₁, O₂,. . . , O_(M−1), O_(M) generated by said M N×1 combiners are output by Moptical fibers.
 5. The all-optical switching system of claim 1, whereinsaid driving signal matrix is provided by a driving system.
 6. Theall-optical switching system of claim 5, wherein said driving system isa computer.
 7. The all-optical switching system of claim 1, wherein theelement S_(P,Q) of the driving signal matrix S is 1 or 0; 0<P≦N; 0<Q≦M;N and M are integers; when S_(P,Q)=1, D′_(P,Q)=D_(P,Q); and whenS_(P,Q)=0, D′_(P,Q)=0.
 8. A method of converting N sets of input opticaldata into M sets of output optical data, comprising the following stepsof: providing N 1×M splitters for receiving N sets of optical data I₁,I₂, . . . , I_(N−1), I_(N) wherein said N splitters split N sets ofoptical data respectively into M sets of optical data to form an N×Moptical data matrix D as below: ${D = \begin{bmatrix}D_{1,1} & D_{1,2} & \ldots & D_{1,{M - 1}} & D_{1,M} \\D_{2,1} & D_{2,2} & \ldots & D_{2,{M - 1}} & D_{2,M} \\\vdots & \vdots & ⋰ & \vdots & \vdots \\D_{{N - 1},1} & D_{{N - 1},2} & \ldots & D_{{N - 1},{M - 1}} & D_{{N - 1},M} \\D_{N,1} & D_{N,2} & \ldots & D_{N,{M - 1}} & D_{N,M}\end{bmatrix}};$

 wherein N and M are integers; D_(1,1), D_(1,2), . . . , D_(1,M−1),D_(1,M) represent the M sets of optical data split I₁ from the firstoptical data by the first 1×M splitter, on the analogy of thisrepresentation; providing N×M matrix switching structure for receivingthe N×M optical data matrix D generated by the splitters and anotherdriving signal matrix S as below: ${S = \begin{bmatrix}S_{1,1} & S_{1,2} & \ldots & S_{1,{M - 1}} & S_{1,M} \\S_{2,1} & S_{2,2} & \ldots & S_{2,{M - 1}} & S_{2,M} \\\vdots & \vdots & ⋰ & \vdots & \vdots \\S_{{N - 1},1} & S_{{N - 1},2} & \ldots & S_{{N - 1},{M - 1}} & S_{{N - 1},M} \\S_{N,1} & S_{N,2} & \ldots & S_{N,{M - 1}} & S_{N,M}\end{bmatrix}};$

 and for generating another N×M optical data matrix D′ as below:${D^{\prime} = \begin{bmatrix}D_{1,1}^{\prime} & D_{1,2}^{\prime} & \ldots & D_{1,{M - 1}}^{\prime} & D_{1,M}^{\prime} \\D_{2,1}^{\prime} & D_{2,2}^{\prime} & \ldots & D_{2,{M - 1}}^{\prime} & D_{2,M}^{\prime} \\\vdots & \vdots & ⋰ & \vdots & \vdots \\D_{{N - 1},1}^{\prime} & D_{{N - 1},2}^{\prime} & \ldots & D_{{N - 1},{M - 1}}^{\prime} & D_{{N - 1},M}^{\prime} \\D_{N,1}^{\prime} & D_{N,2}^{\prime} & \ldots & D_{N,{M - 1}}^{\prime} & D_{N,M}^{\prime}\end{bmatrix}};{and}$

 providing M N×1 combiners for receiving the output N×M optical datamatrix D′ from the N×M matrix switching structure, wherein said Mcombiners combine N sets of optical data into M sets of optical data O₁,O₂, . . . , O_(M−1), O_(M) respectively, and the first optical data O₁is generated by the first combiner after combining N sets of opticaldata D′_(1,1), D′_(2,1), . . . , D′_(N−1), D′_(N,1), on the analogy ofthis generation.
 9. The method of claim 8, wherein said N sets ofoptical data I₁, I₂, . . . , I_(N−1), I_(N) received by said N 1×Msplitters are input by N optical fibers.
 10. The method of claim 8,wherein said M sets of optical data O₁, O₂, . . . , O_(M−1), O_(M)generated by said M N×1 combiners are output by M optical fibers. 11.The method of claim 8, wherein said driving signal matrix is provided bya driving system.
 12. The method of claim 8, wherein the element S_(P,Q)of the driving signal matrix S is 1 or 0; 0<P≦N; 0<Q≦M; N and M areintegers; when S_(P,Q)=1, D′_(P,Q)=D_(P,Q); when S_(P,Q)=0, D′_(P,Q)=0.